python runtime_error ai_generated true

AssertionError: Expected 'foo' to be called with (1,) but was called with (2,)

ID: python/unittest-mock-side-effect-assertion-error

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
0Evidence
2025-08-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

The mock's call arguments don't match the expected arguments, often due to incorrect input or mock configuration.

generic

中文

mock 的调用参数与预期参数不匹配，通常是由于输入错误或 mock 配置错误。

Workarounds

  1. 90% success 
    print(mock.call_args)
assert mock.call_args == call(1,)
  2. 85% success 
    mock.assert_any_call(1)

Dead Ends

Common approaches that don't work:

  1. 80% fail

    This hides the real bug in the code.

  2. 90% fail

    It still fails if arguments don't match.